Fix remote candidate search returning 0 results by mapping preferred_work_mode

test(tests): fix str to enum type errors in test suites

chore: fix all ruff lint errors (174 -> 0), clean up unused imports/vars, fix line lengths

fix: improve UI robustness and test quality

fix: resolve critical bugs - evaluation import cycle, bias detector, slider weights, and 7 more high-severity issues

feat(language): add Hinglish code-mixed processor

feat(extraction): add FieldExtractor pipeline, ProfileStore with lazy loading, and skill matching

chore: commit remaining changes from previous sessions (PRD, plans, tests)

fix(core): three architecture fixes — translation API, constants, vector scoring

feat: Phase 15 documentation + Phase 14 test fixes

chore: create directory structure with __init__.py files and placeholder scripts